US20090222188A1 - Control apparatus for internal combustion engine having motor-driven supercharger - Google Patents
Control apparatus for internal combustion engine having motor-driven supercharger Download PDFInfo
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- US20090222188A1 US20090222188A1 US11/817,347 US81734706A US2009222188A1 US 20090222188 A1 US20090222188 A1 US 20090222188A1 US 81734706 A US81734706 A US 81734706A US 2009222188 A1 US2009222188 A1 US 2009222188A1
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- air flow
- internal combustion
- combustion engine
- supercharger
- inhaled
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0002—Controlling intake air
- F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
- F02B37/12—Control of the pumps
- F02B37/16—Control of the pumps by bypassing charging air
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B29/00—Engines characterised by provision for charging or scavenging not provided for in groups F02B25/00, F02B27/00 or F02B33/00 - F02B39/00; Details thereof
- F02B29/04—Cooling of air intake supply
- F02B29/0406—Layout of the intake air cooling or coolant circuit
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0047—Controlling exhaust gas recirculation [EGR]
- F02D41/0065—Specific aspects of external EGR control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/02—EGR systems specially adapted for supercharged engines
- F02M26/04—EGR systems specially adapted for supercharged engines with a single turbocharger
- F02M26/05—High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
- F02M26/13—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories
- F02M26/22—Arrangement or layout of EGR passages, e.g. in relation to specific engine parts or for incorporation of accessories with coolers in the recirculation passage
- F02M26/23—Layout, e.g. schematics
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to a control apparatus for an internal combustion engine having a motor-driven supercharger.
- the invention relates to a control apparatus for an internal combustion engine having a motor-driven supercharger wherein the compressor can be bypassed through a bypass passage between the downstream and upstream of the supercharger's compressor.
- a motor to the rotation axis of a turbocharger is known in conventional art.
- Such a motor-driven turbocharger is driven to assist the rotation of the compressor. It is therefore possible to attain a necessary level of boost pressure when necessary regardless of whether the exhaust energy supplied from the internals combustion engine is large or small.
- the motor-driven turbocharger can realize high boost pressure by forcibly driving the compressor even when the engine rotation speed is low, that is, when the exhaust gas flow to drive the turbine is low.
- the motor-driven turbocharger has a problem that the likelihood of exceeding the compressor's surge limit is high.
- An internal combustion engine having a motor-driven supercharger disclosed in Japanese Patent Laid-Open No. 2004-332715, is provided with a bypass passage between the upstream and downstream of the compressor to bypass the compressor and a bypass valve which opens and closes this bypass passage.
- the amount of air which passes the compressor can be increased to avoid surge.
- the air boosted by the compressor is partly returned to the upstream of the compressor by opening the bypass valve (hereinafter denoted as “air-bypass”).
- various kinds of control parameters which decide the output of the internal combustion engine are adjusted based on the intake air flow.
- the intake air flow is measured from the signal of an intake air flow sensor such as an air flow meter disposed at the inlet of the intake passage.
- the air flow measured from the signal of the intake air flow sensor immediately after air-bypass is started is different from the actual air flow inhaled into the internal combustion engine. If the signal of the intake air flow sensor does not accurately represent the actual air flow inhaled into the internal combustion engine, the exhaust emission and fuel efficiency may deteriorate since it is not possible to accurately perform fuel injection amount control and other engine controls.
- the present invention has been made in order to solve the above-mentioned problem. It is an object of the present invention to provide a control apparatus for an internal combustion engine having a motor-driven supercharger which is capable of avoiding inaccurate measurement of the air flow inhaled into the internal combustion engine during air-bypass and therefore controlling the internal combustion engine based on the accurately measured intake air flow.
- a control apparatus for an internal combustion engine comprising: a supercharger which is disposed in an intake passage and provided with an electric motor capable of assisting the rotation of the supercharger; a bypass passage which bypasses the downstream side of the supercharger to the upstream side of the supercharger in the intake passage; a bypass valve which opens and closes the bypass passage; and an intake air flow sensor which is disposed upstream of the supercharger in the intake passage and outputs a signal indicative of the air flow inhaled into the intake passage.
- the control apparatus includes: calculation means for calculating the air flow inhaled into the internal combustion engine based on the operational state of the electric motor, the operational state of the bypass valve and the signal of the intake air flow sensor; and control parameter adjustment means for adjusting control parameters which concern the output power of the internal combustion engine based on the air flow inhaled into the internal combustion engine.
- the air flow inhaled into the internal combustion engine is calculated based on the operational states of the electric motor and bypass valve and the signal of the intake air flow sensor and control parameters which concern the output power of the internal combustion engine are adjusted based on the calculated air flow into the combustion engine. Since the air flow inhaled actually into the internal combustion engine is thus determined, it is possible to avoid inaccurate measurement of the air flow inhaled into the internal combustion engine during the execution of air-bypass. Therefore, the internal combustion engine can be controlled based on the accurate intake air even during the execution of air-bypass.
- the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the first aspect wherein the calculation means calculate the air flow inhaled into the internal combustion engine immediately after the bypass valve is opened with the electric motor running by acquiring the bypass air flow going through the bypass passage from the downstream side to the upstream side of the supercharger and using the acquired bypass air flow to correct the intake air flow measured from the signal of the intake air flow sensor.
- the air flow inhaled into the internal combustion engine immediately after air-bypass is started can accurately be calculated by using the bypass air flow to correct the air flow inhaled into the intake passage.
- the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the second aspect wherein the calculation means calculate the bypass air flow from output pressure of a compressor of the supercharger, the output pressure of the compressor being calculated based on the intake air flow and rotation speed of the supercharger, and the opening of the bypass valve.
- the bypass air flow can be measured without installing an air flow sensor in the bypass passage.
- the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the first aspect wherein the calculation means calculate the air flow inhaled into the internal combustion engine immediately after the bypass valve is opened with the electric motor running by smoothing the signal of the intake air flow sensor and taking the intake air flow measured from the smoothed signal as the intake air flow inhaled into the internal combustion engine.
- the signal of the intake air flow sensor is smoothed immediately after air-bypass is started. This can reduce the difference between the intake air flow measured from the signal of the intake air flow sensor and the actual air flow inhaled into the internal combustion engine.
- the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the first aspect wherein the calculation means calculate the air flow inhaled into the internal combustion engine immediately after the bypass valve is opened with the electric motor running by predicting the maximum value of the air flow to be inhaled into the internal combustion engine based on the rotation speed and throttle opening of the internal combustion engine, setting the maximum value as the upper limit to the intake air flow measured from the signal of the intake air flow sensor and taking the result as the air flow inhaled into the internal combustion engine.
- the intake air flow measured from the signal of the intake air flow sensor immediately after air-bypass is started is limited by the maximum air flow to be inhaled into the internal combustion engine.
- the maximum air flow is predicted based on the rotation speed and throttle opening of the internal combustion engine. This can reduce the difference between the intake air flow measured from the signal of the intake air flow sensor and the actual air flow inhaled into the internal combustion engine.
- the control apparatus for an internal combustion engine having a motor-driven supercharger as described in any one of the first through fifth aspects wherein the internal combustion engine further comprises: an EGR apparatus which introduces part of the exhaust gas into the intake passage at an exhaust gas inlet downstream of the throttle; and a gas property sensor which is disposed downstream of the exhaust gas inlet and outputs a signal indicative of the pressure or flow of the gas inhaled into the internal combustion engine, wherein the calculation means calculate the air flow inhaled into the internal combustion engine based on the signal of the gas property sensor when the EGR apparatus is not active, and calculate the air flow inhaled into the internal combustion engine based on the operational state of the electric motor, the operational state of the bypass valve and the signal of the intake air flow sensor when the EGR apparatus is active.
- the air flow inhaled into the internal combustion engine can be measured if a gas property sensor which is disposed downstream of the throttle outputs a signal indicative of the gas pressure or flow.
- a gas property sensor which is disposed downstream of the throttle outputs a signal indicative of the gas pressure or flow.
- the exhaust gas flow causes difference between the gas flow measured from the signal of the gas property sensor and the air flow inhaled actually into the engine.
- the air flow inhaled into the engine can be accurately calculated based on the signal of the gas property sensor.
- the air flow inhaled into the internal combustion engine is calculated based on the operational state of the electric motor, the operational state of the bypass valve and the signal of the intake air flow sensor.
- the air flow inhaled into the engine can accurately be calculated even when exhaust gas is introduced into the intake passage.
- control apparatus for an internal combustion engine having a motor-driven supercharger as described in any one of the first through sixth aspects further comprising surge avoidance means which judges the surge condition of the supercharger when the electric motor is running and, if it is judged that surge avoidance should be done, opens the bypass valve.
- the bypass valve is opened depending on the surge condition of the supercharger, making it possible to avoid surge when the supercharger is driven by the electric motor.
- control apparatus for an internal combustion engine having a motor-driven supercharger as described in any one of the first through seventh aspects, further comprising: torque buildup request prediction means for predicting a torque buildup request from the driver in advance based on road information or vehicle information; and pre-assist means for raising the rotation speed of the supercharger by running the electric motor if the torque buildup request is predicted.
- the rotation speed of the supercharger is raised before torque buildup becomes actually required. This can improve the output response to requests for higher torques.
- a control apparatus for an internal combustion engine comprising: a supercharger which is disposed in an intake passage and provided with an electric motor capable of assisting the rotation of the supercharger; a bypass passage which bypasses the outlet side of the supercharger in the intake passage to the inlet side of the supercharger; a bypass valve which opens and closes the bypass passage; and an intake air flow sensor which is disposed upstream of the supercharger in the intake passage and outputs a signal indicative of the air flow inhaled into the intake passage; wherein, the control apparatus includes: control parameter adjustment means for adjusting control parameters which concern the output power of the internal combustion engine based on the air flow inhaled into the internal combustion engine; torque buildup request prediction means for predicting a torque buildup request from the driver in advance based on road information or vehicle information; pre-assist means for raising the rotation speed of the supercharger by running the electric motor if said torque buildup request is predicted; and valve control means for
- the bypass valve is opened before running the electric motor. This can reduce the difference between the intake air flow measured from the signal of the intake air flow sensor and the air flow inhaled actually into the internal combustion engine since compression of intake air by the supercharger is suppressed. It is therefore possible to control the internal combustion engine based on the accurate air flow inhaled into the engine even during the execution of air-bypass.
- FIG. 1 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger according to the first embodiment of the present invention
- FIG. 2 is a flowchart illustrating an assist control routine that is executed by the first embodiment of the present invention
- FIG. 3 is a flowchart illustrating a pre-assist control routine that is executed by the first embodiment of the present invention
- FIG. 4 is a graph that shows an intake air flow correction method in the pre-assist control according to the first embodiment of the present invention
- FIG. 5 is a graph that shows other intake air flow correction method in the pre-assist control according to the first embodiment of the present invention
- FIG. 6 is a flowchart illustrating a pre-assist control routine that is executed by the second embodiment of the present invention
- FIG. 7 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger according to the third embodiment of the present invention.
- FIG. 8 is a flowchart illustrating an assist control routine that is executed by the third embodiment of the present invention.
- FIGS. 1 through 5 The following will describe a first embodiment of the present invention with reference to FIGS. 1 through 5 .
- FIG. 1 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger to which a control apparatus, the first embodiment of the present invention, is applied.
- the present invention is applied to a gasoline engine (hereinafter, denoted simply as the engine).
- This engine comprises an engine body 2 which has a plurality of cylinders (four cylinders in FIG. 1 ).
- an intake manifold 4 to distribute air the respective cylinders and an exhaust manifold 6 to gather exhaust gas from the respective cylinders.
- This engine is provided with a motor-driven turbocharger (motor assist turbocharger, hereinafter denoted as the MAT) 30 .
- the MAT 30 comprises of a compressor 30 a , a turbine 30 b and an electric motor 30 c disposed between the compressor 30 a and the turbine 30 b .
- the compressor 30 a and the turbine 30 b are coupled together on a connecting shaft.
- the compressor 30 a is driven to rotate by the exhaust energy of the exhaust gas introduced to the turbine 30 b .
- the connecting shaft also serves as the rotor of the electric motor 30 c , making it possible to forcibly drive the compressor 30 a by actuating the electric motor 30 c .
- the coupling shaft is provided with a turbo rotation speed sensor 32 which outputs a signal indicative of the rotation speed (number of rotations per certain time) of the compressor 30 a.
- the compressor 30 a is disposed half way between the intake passages 8 and 10 which lead to the intake manifold 4 .
- the intake passage 10 which connects the outlet of the compressor 30 a to the intake manifold 4 is provided with an intercooler 36 to cool the boosted air.
- the intake passage 10 is also provided with a throttle valve 20 for controlling the air flow inhaled into the engine body 2 .
- the air to be supplied to the engine body 2 is taken in from the atmosphere via an air cleaner 16 .
- the intake passage 8 which connects the air cleaner 16 to the inlet of the compressor 30 a is provided with an air flow meter 52 which outputs a signal indicative of the air flow inhaled into the intake passage 8 .
- This engine has a bypass passage 40 which bypasses the compressor 30 a by connecting the outlet and inlet of the compressor 30 a .
- One end of the bypass passage 40 is connected to the downstream of the air flow meter 52 in the intake passage 8 while the other end is connected to the upstream of the throttle valve 20 in the intake passage 10 .
- the bypass passage 40 is provided with a bypass valve 42 for controlling the amount of air (bypassed air) which flows therein.
- an exhaust passage 12 is connected to the inlet of the turbine 30 b .
- the other end of the exhaust passage 12 is connected to the exhaust manifold 6 .
- the exhaust gas gathered by the exhaust manifold 6 from the respective cylinders is supplied to the turbine 30 b through the exhaust passage 12 .
- the other exhaust passage 14 is connected to the outlet of the turbine 30 b .
- a catalyst 18 is disposed for clarifying the exhaust gas.
- an ECU 50 As a control unit for general control of the whole engine, an ECU (Electronic Control Unit) 50 is provided.
- This ECU 50 includes a motor controller which controls the power to be supplied to the electric motor 30 c , that is, controls the rotation of the MAT 30 .
- various devices such as the throttle valve 20 and bypass valve 42 are connected to the output side of the ECU 50 .
- the input side of the ECU 50 is connected to various kinds of sensors including not only the aforementioned air flow meter 52 and turbo rotation speed sensor 32 but also an engine rotation speed sensor 54 which outputs a signal indicative the engine rotation speed and an accelerator opening sensor 56 which outputs a signal indicative of the accelerator opening.
- road information and vehicle information are also input to the ECU 50 .
- the road information includes the current road's curvature, inclination, etc.
- the vehicle information includes the vehicle's distance from the nearest one in front of it, steering angle, etc.
- the road information can be obtained from, for example, a GPS-used navigation system.
- the vehicle information is available from on-vehicle sensors (such as a forward radar). Based on the respective sensor signals and other input information, the ECU 50 drives each device according to a certain control program.
- One of the engine controls the ECU 50 implements is fuel injection amount control to control the amount of fuel injected from the injectors (not illustrated).
- a fuel injection amount is calculated based on the intake air flow measured from the signal of the air flow meter 52 so as to make the air-fuel ratio equal to the predetermined target ratio wherein the air-fuel ratio is the mass of air inhaled into the engine system divided by the mass of fuel injected into the cylinders.
- assist control Another engine control the ECU 50 performs is assist control to assist the rotation of the compressor 30 a by the electric motor 30 c .
- the assist control is performed by a separate routine concurrently with the above-mentioned fuel injection amount control.
- bypass valve 42 opening and closing control is also performed in order to prevent the compressor 30 a from causing surge.
- the fuel injection amount control uses the signal of the air flow meter 52 . To satisfactorily maintain the exhaust emission and fuel efficiency, the fuel injection amount must be controlled to the target amount based on the actual amount of air inhaled into the engine body 2 .
- FIG. 2 provides a flowchart showing an assist control routine which the ECU 50 executes. Execution of this assist control routine includes correction of the intake air flow.
- signals entered into the ECU 50 from individual sensors are processed.
- signals from the accelerator opening sensor 56 , engine rotation speed sensor 54 , turbo rotation speed sensor 32 and air flow meter 52 are used.
- the ECU 50 refers to an operating state judgment map prepared in advance, and from the engine rotation speed and accelerator opening, judges whether the current operating state of the engine needs motor assist. Motor assist is judged needed, for example, if a higher torque is needed although the exhaust energy is too low to drive the MAT 30 (low speed and high load state). If the current operating state of the engine needs motor assist, the “assist start/continue” condition is met. On the other hand, if the operating state does not need motor assist, this routine terminates since the “assist start/continue” condition is not met.
- step 104 a target turbo rotation speed is determined for the MAT 30 based on the input signals processed at step 100 .
- the ECU 50 determines the target turbo rotation speed from a multi-dimensional map (motor control map) where the engine rotation speed, accelerator opening and throttle opening are represented along their corresponding axes.
- the ECU 50 supplies power to the electric motor 30 c according to the target turbo rotation speed to start the assist by the electric motor 30 c (step 106 ).
- a “bypass valve 42 open” condition means that the compressor 30 a has reached the surge limit. Whether the surge limit is reached can be judged from the pressure ratio of the output pressure to the input pressure (atmospheric pressure) of the compressor 30 a and the intake air flow indicated by the signal of the air flow meter 52 . If the relation between the pressure ratio and the intake air flow exceeds a predefined surge line, it is judged that the compressor 30 a has reached the surge limit.
- the output pressure of the compressor 30 a may be measured from the signal of this pressure sensor.
- the output pressure of the compressor 30 a is calculated from the turbo rotation speed measured by the turbo rotation speed meter 32 and the intake air flow. Specifically, the output pressure of the compressor 30 a is determined from a map where the turbo rotation speed and the intake air flow are represented along their corresponding axes.
- bypass valve open condition met at step 108 , namely the compressor 30 a has reached the surge limit
- the bypass valve 42 is opened (step 110 ).
- the bypass valve 42 is normally closed. If the bypass valve 42 is opened, the air compressed by the compressor 30 a is partly returned to the upstream of the compressor 30 a through the bypass passage 40 . Thus, the compressor 30 a is prevented from causing surge since air-bypass is performed to increase the amount of air which passes the compressor 30 a.
- bypass valve 42 If the bypass valve 42 is opened to perform air-bypass at step 110 , the amount of air flowing through the bypass passage 40 settles to a certain steady level. After the steady level is reached, the intake air flow indicated by the signal of the air flow meter 52 agrees with the amount of air which is actually inhaled into the engine body 2 . However, until the bypass passage 40 is filled with air to settle the amount of air flowing through it, more air is inhaled into the intake passage 8 than inhaled actually into the engine body 2 . Therefore, a transient difference occurs between the intake air flow indicated by the signal of the air flow meter 52 and the air flow inhaled into the engine body 2 .
- correction of the intake air flow measured from the signal of the air flow meter 52 is performed at step 112 until the bypass air flow settles to a steady level.
- the amount of air which is actually inhaled into the engine body 2 is calculated by subtracting the amount of bypassed air (bypass air flow) from the amount of intake air measured from the signal of the air flow meter 52 (measured intake air flow).
- the bypass air flow can be calculated from the pressure difference between the upstream and downstream of the bypass valve 42 , or the difference between the output pressure and input pressure (atmospheric pressure) of the compressor 30 a , and the aperture area of the bypass valve 42 .
- bypass air flow settles after air-bypass was started, correction of the intake air flow according to the above-mentioned equation (1) is terminated. Since then, the intake air flow measured from the signal of the air flow meter 52 is directly used in the fuel injection amount control. Whether the bypass air flow has settled can be judged from the change of the pressure difference between the upstream and downstream of the bypass valve 42 , namely the change of the difference between output pressure and input pressure of the compressor 30 a.
- step 108 If the “bypass valve 42 open” condition is not met at step 108 , that is, the compressor 30 a has not reached the surge limit, air-bypass is not performed since processing of step 110 is skipped. In this case, the intake air flow is not corrected since processing of step 112 is also skipped. That is, while the bypass valve 42 is closed, the intake air flow measured from the signal of the air flow meter 52 is directly used in the fuel injection amount control.
- step 114 it is judged whether a “bypass valve 42 close” condition is met.
- the “bypass valve 42 close” condition means that the surge of the compressor 30 a is avoided. It is judged that the surge of the compressor 30 a is avoided if the relation between the ratio of the output pressure to the input pressure of the compressor 30 a and the intake air flow falls below the surge line. If the “bypass valve close” condition is met, that is, the surge of the compressor 30 a is avoided, the bypass valve 42 is closed (step 116 ). If the “bypass valve close” condition is not met, the bypass valve 42 is kept open and processing of the step 116 and the subsequent steps are skipped.
- the bypass valve 42 is closed, it is judged at the next step 118 whether a “motor assist stop” condition is met. Specifically, the ECU 50 compares the actual turbo rotation speed measured by the turbo rotation speed sensor 32 with the target turbo rotation speed determined at step 104 . If the actual turbo rotation speed has reached the target turbo rotation speed, the “motor assist stop” condition is met. Until the “motor assist stop” condition is met, processing of the next step 120 is skipped to continue the motor assist. If the “motor assist stop” condition is met, power supply from the ECU 50 to the electric motor 30 c is stopped to terminate the assist by the electric motor 30 c (step 120 ).
- the fuel injection amount control can be performed based on the accurate intake air flow. That is, it is possible to realize the target air-fuel ratio to satisfactorily maintain the exhaust emission and fuel efficiency even when air-bypass is performed in order to avoid surge.
- calculation means according to the first aspect of the present invention is realized by the ECU 50 through execution of the aforementioned routine's step 112 .
- control parameter adjustment means according to the first aspect of the present invention is realized by the ECU 50 through execution of the fuel injection amount control based on the intake air flow corrected at step 112 .
- surge avoidance means according to the seventh aspect of the present invention is realized by the CPU 50 through execution of step 108 .
- the ECU 50 in the present embodiment can perform pre-assist control.
- the pre-assist control predicts a torque buildup request from the driver and raises the turbo rotation speed by driving the electric motor 30 c before a higher torque becomes actually needed.
- the time lag required for the boost pressure to be raised by the rotation of the compressor 30 a can be eliminated. It is therefore possible to improve the output response to requests for higher torques for acceleration, climbing and so on.
- this pre-assist control is performed by a separate routine concurrently with the above-mentioned fuel injection amount control.
- bypass valve 42 is opened to perform air-bypass so as to prevent the compressor 30 a from causing surge while the turbo rotation speed is raised quickly. Therefore, as in the assist control, in a transient state immediately after air-bypass is started, a transient difference occurs between the amount of intake air measured from the signal of the air flow meter 52 and the amount of air inhaled actually into the engine body 2 .
- FIG. 3 provides a flowchart showing an pre-assist control routine which the ECU 50 executes. Execution of this pre-assist control routine includes correction of the intake air flow.
- signals entered into the ECU 50 from individual sensors are processed.
- signals from the accelerator opening sensor 56 , engine rotation speed sensor 54 , turbo rotation speed sensor 32 and air flow meter 52 are used.
- Road information and vehicle information are also used in the pre-assist control.
- the ECU 50 judges whether the current traveling situation of the vehicle needs the pre-assist according to road information and vehicle information.
- the pre-assist is judged necessary if higher torque is expected to be required, for example, when the vehicle is going to be started on a slope, when the vehicle is approaching to an upward slope and when the vehicle is entering a straight road from a curved road. If the current traveling situation of the vehicle requires the pre-assist, the “pre-assist start/continue” condition is met. On the other hand, if the situation does not require the pre-assist, this routine is terminated since the “pre-assist start/continue” condition is not met.
- step 204 a target turbo rotation speed is determined for the MAT 30 based on the input signals processed at step 200 .
- the ECU 50 determines the target turbo rotation speed from a multi-dimensional pre-assist map (motor control map) where the engine rotation speed, accelerator opening and throttle opening are represented along their corresponding axes.
- the ECU 50 supplies power to the electric motor 30 c according to the target turbo rotation speed to start the assist by the electric motor 30 c (step 206 ).
- the bypass valve 42 is opened (step 208 ). Since opening the bypass valve 42 bypasses the output side to the input side of the compressor 30 a , the rise of the output pressure of the compressor 30 a is suppressed although the turbo rotation speed rises. This makes it possible to quickly raise the turbo rotation speed to the target speed while avoiding the surge of the compressor 30 a.
- the intake air flow measured from the signal of the air flow meter 52 is corrected at the next step 210 .
- correction is done by smoothing the signal of the air flow meter 52 .
- the intake air flow is measured from the smoothed signal. Note that although the signal is usually smoothed to remove noise, the signal is smoothed here several ten times more than usual. Determining the intake air flow from the smoothed signal can approximate the air flow inhaled actual into the engine body 2 (actual intake air flow) as shown FIG. 4 , resulting in a reduced difference between the intake air flow measured from the signal of the air flow meter 52 and the actual intake air flow.
- step 212 it is judged whether a “bypass valve 42 close” condition is met.
- the “bypass valve 42 close” condition means that a torque buildup request is issued from the driver. Whether a torque buildup request is present can be judged from the engine rotation speed and the accelerator opening. If a torque buildup request is issued, the bypass valve 42 is closed (step 214 ) to raise the output pressure of the compressor 30 a . On the other hand, if the “bypass valve close” condition is not met, the bypass valve 42 is kept open and processing of step 214 and the subsequent steps are skipped.
- the bypass valve 42 is closed, it is judged at the next step 216 whether a “motor assist stop” condition is met. Specifically, the ECU 50 compares the actual turbo rotation speed measured by the turbo rotation speed sensor 32 with the target turbo rotation speed determined at step 204 . If the actual turbo rotation speed has reached the target turbo rotation speed, the “motor assist stop” condition is met. Until the “motor assist stop” condition is met, processing of the next step 218 is skipped to continue the motor assist. If the “motor assist stop” condition is met, power supply from the ECU 50 to the electric motor 30 c is stopped to terminate the assist by the electric motor 30 c (step 218 ).
- the fuel injection amount control can be performed based on the accurate intake air flow. That is, it is possible to realize the target air-fuel ratio and satisfactorily maintain the exhaust emission and fuel efficiency even during the pre-assist.
- calculation means is realized by the ECU 50 through execution of the aforementioned routine's step 210 .
- control parameter adjustment means according to the first aspect of the present invention is realized by the ECU 50 through execution of the fuel injection amount control based on the intake air flow corrected at step 210 .
- torque buildup request prediction means and “pre-assist means” according to the eighth aspect of the present invention are realized by the CPU 50 through execution of steps 202 and 206 , respectively.
- the intake air flow during the pre-assist is corrected in the above-mentioned embodiment by smoothing the signal of the air flow meter 52 , it is also possible to use simpler correction methods.
- One example is to predict the maximum intake air flow into the engine body 2 from the engine rotation speed and throttle opening and set the maximum value as the upper limit of the intake air flow. By restricting the intake air flow measured from the signal of the air flow meter 52 below the upper limit, it is possible to approximate the actual air flow into the engine body 2 (actual intake air flow) or reduce the difference between the intake air flow measured from the signal of the air flow meter 52 and the actual intake air flow.
- bypass valve 42 is opened immediately after the motor assist is started for pre-assist
- the bypass valve 42 may be kept closed in the same manner as the assist control routine until the compressor 30 a reaches the surge limit. Correction of the intake air flow by smoothing the signal of the air flow meter 52 or setting an upper limit to the intake air flow can be executed immediately after the motor assist is started regardless of whether the bypass valve 42 is opened or not.
- a control apparatus for an internal combustion engine having a motor-driven supercharger is also implemented in the same configuration as FIG. 1 .
- the control apparatus is implemented by making the ECU 50 execute a routine shown in FIG. 6 instead of the routine shown in FIG. 3 .
- FIG. 6 provides a flowchart showing a pre-assist control routine which is executed by the ECU 50 .
- Each step of processing in the routine of FIG. 6 is given the same step number as the corresponding step, if any, in the routine of FIG. 3 if there is no difference in terms of processing.
- description of processing is omitted unless not already described.
- the bypass valve 42 is opened (step 220 ) before motor assist is started. That is, the outlet side of the compressor 30 a is bypassed by the opened bypass valve 42 to the inlet side before the ECU 50 starts the assist of the electric motor 30 c by supplying power, which is determined according to the target turbo rotation speed, from the ECU 50 to the electric motor 30 c (step 222 ).
- bypass valve 42 Since the bypass valve 42 is opened before the electric motor 30 c is started to run, compression of the intake air by the compressor 30 a is suppressed, resulting in a smaller pressure difference between the inlet and outlet of the compressor 30 a . Therefore, since the air which flows into the bypass passage 40 is suppressed, almost all of the air which passes the compressor 30 a is directly inhaled into the engine body 2 .
- the fuel injection amount control can be done based on the accurate intake air flow by directly using the intake air flow measured from the signal of the air flow meter 52 .
- control parameter adjustment means according to the ninth aspect of the present invention is realized by the ECU 50 through execution of the fuel injection amount control.
- torque buildup request prediction means “pre-assist means”
- valve control means are realized by the CPU 50 through execution of steps 202 , 222 and 220 , respectively.
- FIG. 7 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger where a third control apparatus embodiment of the present invention is applied.
- Each component in FIG. 7 is given the same reference numeral as the corresponding one, if any, shown in FIG. 1 .
- configurational description is omitted unless not already described.
- the engine according to the present embodiment is different from the engine according to the first embodiment in that an EGR is included.
- an EGR passage 22 is connected to the intake passage 10 between the throttle valve 20 and the intake manifold 4 .
- the opposite end of the EGR passage 22 is connected to the exhaust manifold 6 .
- the EGR passage 22 is provided with an EGR cooler 26 to cool the EGR gas which flows therein. Downstream of the EGR cooler 26 , the EGR passage 22 is provided with an EGR valve 24 to control the passage area of the EGR passage 22 .
- EGR passage 22 , EGR valve 24 and EGR cooler 26 constitute an EGR apparatus.
- EGR gas part of the exhaust gas
- EGR flow The amount of EGR gas introduced into the intake passage 10 (EGR flow) can be controlled by the opening of the EGR valve 24 .
- the opening of the EGR valve 24 is controlled by the ECU 50 based on the operating state of the engine.
- the intake passage 10 Downstream of the connection with the EGR passage 22 , the intake passage 10 is provided a boost pressure sensor 58 .
- the boost pressure sensor 58 outputs a signal indicative of the internal air pressure of the intake passage 10 . Since the air pressure in the intake passage 10 is consistent with the air flow therein, it can be said that the boost pressure sensor 58 outputs a signal indicative of the air flow in the intake passage 10 . Therefore, from the signal of the boost pressure sensor 58 , it is possible to measure the air flow inhaled into the engine body 2 via the intake passage 10 .
- the boost pressure sensor 58 is connected to the input side of the ECU 50 . The signal of the boost pressure sensor 58 is used by the ECU 50 to control the engine.
- FIG. 8 provides a flowchart showing an assist control routine which the ECU 50 executes in the present embodiment.
- Each step of processing in the routine of FIG. 8 is given the same step number as the corresponding step, if any, in the routine of FIG. 2 if there is no difference in terms of processing.
- description of processing is omitted unless not already described.
- calculation of the amount of intake air is switched depending on whether the EGR valve 24 is open. Specifically, as shown in FIG. 8 , after the bypass valve 42 is opened at step 110 , it is judged whether the EGR valve 24 is open (step 122 ). If the EGR valve 24 is closed, the air flow inhaled into the engine body 2 is calculated from the signal of the boost pressure sensor 58 (step 124 ). Using the signal of the boost pressure sensor 58 makes it possible to accurately calculate the air flow inhaled into the engine body 2 not under influence of the air-bypass.
- “calculation means” according to the sixth aspect of the present invention is realized by the ECU 50 through execution of step 122 , 124 or 112 .
- the boost pressure sensor 58 corresponds to the “gas property sensor” according to the sixth aspect of the present invention.
- Pre-assist control in the first embodiment smoothens the signal of the air flow meter 52 during the execution of air-bypass.
- the intake air flow measured from the smoothed signal is taken as the air flow inhaled into the engine body 2 .
- This may be modified so as to smooth the signal of the air flow meter 52 only during a transient period just after air-bypass is started.
- the air flow inhaled into the engine body 2 just after air-bypass is started may also be determined by correcting the intake air flow measured from the signal of the air flow meter 52 , namely subtracting the bypass air flow from the measured intake air flow.
- the third embodiment may be modified so as to perform the pre-assist control by using either the pre-assist control method in the first embodiment or that in the second embodiment. While the EGR apparatus is not active, the air flow inhaled into the engine body 2 may also be calculated from the signal of the boost pressure sensor 58 in the same manner as the assist control in the third embodiment.
- the third embodiment has the boost pressure sensor 58 disposed downstream of the throttle valve 20 in the intake passage 10
- an air flow meter which outputs a signal indicative of the air flow may be disposed in place of the boost pressure sensor 58 .
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- General Engineering & Computer Science (AREA)
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Abstract
Description
- The present invention relates to a control apparatus for an internal combustion engine having a motor-driven supercharger. In particulars the invention relates to a control apparatus for an internal combustion engine having a motor-driven supercharger wherein the compressor can be bypassed through a bypass passage between the downstream and upstream of the supercharger's compressor.
- Setting a motor to the rotation axis of a turbocharger is known in conventional art. Such a motor-driven turbocharger is driven to assist the rotation of the compressor. It is therefore possible to attain a necessary level of boost pressure when necessary regardless of whether the exhaust energy supplied from the internals combustion engine is large or small. Thus, the motor-driven turbocharger can realize high boost pressure by forcibly driving the compressor even when the engine rotation speed is low, that is, when the exhaust gas flow to drive the turbine is low. However, the motor-driven turbocharger has a problem that the likelihood of exceeding the compressor's surge limit is high.
- As a method to avoid surge, it is effective to secure a certain amount of air which passes the compressor. An internal combustion engine having a motor-driven supercharger, disclosed in Japanese Patent Laid-Open No. 2004-332715, is provided with a bypass passage between the upstream and downstream of the compressor to bypass the compressor and a bypass valve which opens and closes this bypass passage. According to this technique, the amount of air which passes the compressor can be increased to avoid surge. For this purpose, the air boosted by the compressor is partly returned to the upstream of the compressor by opening the bypass valve (hereinafter denoted as “air-bypass”).
- In the internal combustion engine, various kinds of control parameters which decide the output of the internal combustion engine, such as the fuel injection amount, are adjusted based on the intake air flow. Generally, the intake air flow is measured from the signal of an intake air flow sensor such as an air flow meter disposed at the inlet of the intake passage.
- In this internal combustion engine having a motor-driven turbocharger, however, the air which has passed the compressor partly flows into the bypass passage if the bypass valve is opened to avoid surge. Until the pressure difference between the upstream and downstream of the bypass valve is settled as the bypass passage is filled with air, the amount of air inhaled into the intake passage is larger than the amount of air inhaled into the internal combustion engine.
- Due to this, the air flow measured from the signal of the intake air flow sensor immediately after air-bypass is started is different from the actual air flow inhaled into the internal combustion engine. If the signal of the intake air flow sensor does not accurately represent the actual air flow inhaled into the internal combustion engine, the exhaust emission and fuel efficiency may deteriorate since it is not possible to accurately perform fuel injection amount control and other engine controls.
- The present invention has been made in order to solve the above-mentioned problem. It is an object of the present invention to provide a control apparatus for an internal combustion engine having a motor-driven supercharger which is capable of avoiding inaccurate measurement of the air flow inhaled into the internal combustion engine during air-bypass and therefore controlling the internal combustion engine based on the accurately measured intake air flow.
- In accomplishing the above object, according to a first aspect of the present invention, there is provided a control apparatus for an internal combustion engine comprising: a supercharger which is disposed in an intake passage and provided with an electric motor capable of assisting the rotation of the supercharger; a bypass passage which bypasses the downstream side of the supercharger to the upstream side of the supercharger in the intake passage; a bypass valve which opens and closes the bypass passage; and an intake air flow sensor which is disposed upstream of the supercharger in the intake passage and outputs a signal indicative of the air flow inhaled into the intake passage. The control apparatus includes: calculation means for calculating the air flow inhaled into the internal combustion engine based on the operational state of the electric motor, the operational state of the bypass valve and the signal of the intake air flow sensor; and control parameter adjustment means for adjusting control parameters which concern the output power of the internal combustion engine based on the air flow inhaled into the internal combustion engine.
- According to the first aspect of the present invention, the air flow inhaled into the internal combustion engine is calculated based on the operational states of the electric motor and bypass valve and the signal of the intake air flow sensor and control parameters which concern the output power of the internal combustion engine are adjusted based on the calculated air flow into the combustion engine. Since the air flow inhaled actually into the internal combustion engine is thus determined, it is possible to avoid inaccurate measurement of the air flow inhaled into the internal combustion engine during the execution of air-bypass. Therefore, the internal combustion engine can be controlled based on the accurate intake air even during the execution of air-bypass.
- According to a second aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the first aspect, wherein the calculation means calculate the air flow inhaled into the internal combustion engine immediately after the bypass valve is opened with the electric motor running by acquiring the bypass air flow going through the bypass passage from the downstream side to the upstream side of the supercharger and using the acquired bypass air flow to correct the intake air flow measured from the signal of the intake air flow sensor.
- According to the second aspect of the present invention, the air flow inhaled into the internal combustion engine immediately after air-bypass is started can accurately be calculated by using the bypass air flow to correct the air flow inhaled into the intake passage.
- According to a third aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the second aspect, wherein the calculation means calculate the bypass air flow from output pressure of a compressor of the supercharger, the output pressure of the compressor being calculated based on the intake air flow and rotation speed of the supercharger, and the opening of the bypass valve.
- According to the third aspect of the present invention, the bypass air flow can be measured without installing an air flow sensor in the bypass passage. In addition, it is not necessary to install a pressure sensor to measure the output pressure of the compressor.
- According to a fourth aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the first aspect, wherein the calculation means calculate the air flow inhaled into the internal combustion engine immediately after the bypass valve is opened with the electric motor running by smoothing the signal of the intake air flow sensor and taking the intake air flow measured from the smoothed signal as the intake air flow inhaled into the internal combustion engine.
- According to the fourth aspect of the present invention, the signal of the intake air flow sensor is smoothed immediately after air-bypass is started. This can reduce the difference between the intake air flow measured from the signal of the intake air flow sensor and the actual air flow inhaled into the internal combustion engine.
- According to a fifth aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in the first aspect, wherein the calculation means calculate the air flow inhaled into the internal combustion engine immediately after the bypass valve is opened with the electric motor running by predicting the maximum value of the air flow to be inhaled into the internal combustion engine based on the rotation speed and throttle opening of the internal combustion engine, setting the maximum value as the upper limit to the intake air flow measured from the signal of the intake air flow sensor and taking the result as the air flow inhaled into the internal combustion engine.
- According to the fifth aspect of the present invention, the intake air flow measured from the signal of the intake air flow sensor immediately after air-bypass is started is limited by the maximum air flow to be inhaled into the internal combustion engine. The maximum air flow is predicted based on the rotation speed and throttle opening of the internal combustion engine. This can reduce the difference between the intake air flow measured from the signal of the intake air flow sensor and the actual air flow inhaled into the internal combustion engine.
- According to a sixth aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in any one of the first through fifth aspects, wherein the internal combustion engine further comprises: an EGR apparatus which introduces part of the exhaust gas into the intake passage at an exhaust gas inlet downstream of the throttle; and a gas property sensor which is disposed downstream of the exhaust gas inlet and outputs a signal indicative of the pressure or flow of the gas inhaled into the internal combustion engine, wherein the calculation means calculate the air flow inhaled into the internal combustion engine based on the signal of the gas property sensor when the EGR apparatus is not active, and calculate the air flow inhaled into the internal combustion engine based on the operational state of the electric motor, the operational state of the bypass valve and the signal of the intake air flow sensor when the EGR apparatus is active.
- The air flow inhaled into the internal combustion engine can be measured if a gas property sensor which is disposed downstream of the throttle outputs a signal indicative of the gas pressure or flow. However, if exhaust gas is introduced into the intake passage by an EGR apparatus, the exhaust gas flow causes difference between the gas flow measured from the signal of the gas property sensor and the air flow inhaled actually into the engine. According to the sixth aspect of the present invention, when the EGR apparatus is not active, the air flow inhaled into the engine can be accurately calculated based on the signal of the gas property sensor. When the EGR is active, the air flow inhaled into the internal combustion engine is calculated based on the operational state of the electric motor, the operational state of the bypass valve and the signal of the intake air flow sensor. Thus, the air flow inhaled into the engine can accurately be calculated even when exhaust gas is introduced into the intake passage.
- According to a seventh aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in any one of the first through sixth aspects, further comprising surge avoidance means which judges the surge condition of the supercharger when the electric motor is running and, if it is judged that surge avoidance should be done, opens the bypass valve.
- According to the seventh aspect of the present invention, the bypass valve is opened depending on the surge condition of the supercharger, making it possible to avoid surge when the supercharger is driven by the electric motor.
- According to an eighth aspect of the present invention, there is provided the control apparatus for an internal combustion engine having a motor-driven supercharger as described in any one of the first through seventh aspects, further comprising: torque buildup request prediction means for predicting a torque buildup request from the driver in advance based on road information or vehicle information; and pre-assist means for raising the rotation speed of the supercharger by running the electric motor if the torque buildup request is predicted.
- According to the eighth aspect of the present invention, the rotation speed of the supercharger is raised before torque buildup becomes actually required. This can improve the output response to requests for higher torques.
- In accomplishing the above object, according to a ninth aspect of the present invention, there is provided a control apparatus for an internal combustion engine comprising: a supercharger which is disposed in an intake passage and provided with an electric motor capable of assisting the rotation of the supercharger; a bypass passage which bypasses the outlet side of the supercharger in the intake passage to the inlet side of the supercharger; a bypass valve which opens and closes the bypass passage; and an intake air flow sensor which is disposed upstream of the supercharger in the intake passage and outputs a signal indicative of the air flow inhaled into the intake passage; wherein, the control apparatus includes: control parameter adjustment means for adjusting control parameters which concern the output power of the internal combustion engine based on the air flow inhaled into the internal combustion engine; torque buildup request prediction means for predicting a torque buildup request from the driver in advance based on road information or vehicle information; pre-assist means for raising the rotation speed of the supercharger by running the electric motor if said torque buildup request is predicted; and valve control means for opening the bypass valve before running the electric motor if the torque buildup request is predicted.
- According to the ninth aspect of the present invention, when the electric motor is going to be run to raise the rotation speed of the supercharger before torque buildup becomes actually required, the bypass valve is opened before running the electric motor. This can reduce the difference between the intake air flow measured from the signal of the intake air flow sensor and the air flow inhaled actually into the internal combustion engine since compression of intake air by the supercharger is suppressed. It is therefore possible to control the internal combustion engine based on the accurate air flow inhaled into the engine even during the execution of air-bypass.
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FIG. 1 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger according to the first embodiment of the present invention; -
FIG. 2 is a flowchart illustrating an assist control routine that is executed by the first embodiment of the present invention; -
FIG. 3 is a flowchart illustrating a pre-assist control routine that is executed by the first embodiment of the present invention; -
FIG. 4 is a graph that shows an intake air flow correction method in the pre-assist control according to the first embodiment of the present invention; -
FIG. 5 is a graph that shows other intake air flow correction method in the pre-assist control according to the first embodiment of the present invention; -
FIG. 6 is a flowchart illustrating a pre-assist control routine that is executed by the second embodiment of the present invention; -
FIG. 7 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger according to the third embodiment of the present invention; and -
FIG. 8 is a flowchart illustrating an assist control routine that is executed by the third embodiment of the present invention. - The following will describe a first embodiment of the present invention with reference to
FIGS. 1 through 5 . -
FIG. 1 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger to which a control apparatus, the first embodiment of the present invention, is applied. In the present embodiment, the present invention is applied to a gasoline engine (hereinafter, denoted simply as the engine). This engine comprises anengine body 2 which has a plurality of cylinders (four cylinders inFIG. 1 ). To theengine body 2, anintake manifold 4 to distribute air the respective cylinders and anexhaust manifold 6 to gather exhaust gas from the respective cylinders. - This engine is provided with a motor-driven turbocharger (motor assist turbocharger, hereinafter denoted as the MAT) 30. The
MAT 30 comprises of acompressor 30 a, aturbine 30 b and anelectric motor 30 c disposed between thecompressor 30 a and theturbine 30 b. Thecompressor 30 a and theturbine 30 b are coupled together on a connecting shaft. Thecompressor 30 a is driven to rotate by the exhaust energy of the exhaust gas introduced to theturbine 30 b. The connecting shaft also serves as the rotor of theelectric motor 30 c, making it possible to forcibly drive thecompressor 30 a by actuating theelectric motor 30 c. In addition, the coupling shaft is provided with a turborotation speed sensor 32 which outputs a signal indicative of the rotation speed (number of rotations per certain time) of thecompressor 30 a. - The
compressor 30 a is disposed half way between theintake passages intake manifold 4. Theintake passage 10 which connects the outlet of thecompressor 30 a to theintake manifold 4 is provided with anintercooler 36 to cool the boosted air. Near theintake manifold 4, theintake passage 10 is also provided with athrottle valve 20 for controlling the air flow inhaled into theengine body 2. - The air to be supplied to the
engine body 2 is taken in from the atmosphere via anair cleaner 16. Theintake passage 8 which connects theair cleaner 16 to the inlet of thecompressor 30 a is provided with anair flow meter 52 which outputs a signal indicative of the air flow inhaled into theintake passage 8. - This engine has a
bypass passage 40 which bypasses thecompressor 30 a by connecting the outlet and inlet of thecompressor 30 a. One end of thebypass passage 40 is connected to the downstream of theair flow meter 52 in theintake passage 8 while the other end is connected to the upstream of thethrottle valve 20 in theintake passage 10. Thebypass passage 40 is provided with abypass valve 42 for controlling the amount of air (bypassed air) which flows therein. - To the inlet of the
turbine 30 b, anexhaust passage 12 is connected. The other end of theexhaust passage 12 is connected to theexhaust manifold 6. The exhaust gas gathered by theexhaust manifold 6 from the respective cylinders is supplied to theturbine 30 b through theexhaust passage 12. To the outlet of theturbine 30 b, theother exhaust passage 14 is connected. In thisexhaust passage 14, acatalyst 18 is disposed for clarifying the exhaust gas. - As a control unit for general control of the whole engine, an ECU (Electronic Control Unit) 50 is provided. This
ECU 50 includes a motor controller which controls the power to be supplied to theelectric motor 30 c, that is, controls the rotation of theMAT 30. In addition to theelectric motor 30 c, various devices such as thethrottle valve 20 andbypass valve 42 are connected to the output side of theECU 50. - On the other hand, the input side of the
ECU 50 is connected to various kinds of sensors including not only the aforementionedair flow meter 52 and turborotation speed sensor 32 but also an enginerotation speed sensor 54 which outputs a signal indicative the engine rotation speed and anaccelerator opening sensor 56 which outputs a signal indicative of the accelerator opening. In addition to these sensor signals, road information and vehicle information are also input to theECU 50. The road information includes the current road's curvature, inclination, etc. The vehicle information includes the vehicle's distance from the nearest one in front of it, steering angle, etc. The road information can be obtained from, for example, a GPS-used navigation system. The vehicle information is available from on-vehicle sensors (such as a forward radar). Based on the respective sensor signals and other input information, theECU 50 drives each device according to a certain control program. - One of the engine controls the
ECU 50 implements is fuel injection amount control to control the amount of fuel injected from the injectors (not illustrated). In this fuel injection amount control, a fuel injection amount is calculated based on the intake air flow measured from the signal of theair flow meter 52 so as to make the air-fuel ratio equal to the predetermined target ratio wherein the air-fuel ratio is the mass of air inhaled into the engine system divided by the mass of fuel injected into the cylinders. - Another engine control the
ECU 50 performs is assist control to assist the rotation of thecompressor 30 a by theelectric motor 30 c. The assist control is performed by a separate routine concurrently with the above-mentioned fuel injection amount control. During execution of the assist control,bypass valve 42 opening and closing control is also performed in order to prevent thecompressor 30 a from causing surge. - However, if the
bypass valve 42 is opened to execute air-bypass while theelectric motor 30 c is operating, a transient difference occurs between the amount of intake air measured from theair flow meter 52 and the amount of air inhaled actually into theengine body 2. As mentioned above, the fuel injection amount control uses the signal of theair flow meter 52. To satisfactorily maintain the exhaust emission and fuel efficiency, the fuel injection amount must be controlled to the target amount based on the actual amount of air inhaled into theengine body 2. - Accordingly, fuel injection amount control and assist control are interrelated as described below in the present embodiment. The intake air flow is corrected according to the situation of the assist control. The fuel injection amount can be controlled based on the corrected intake air flow.
FIG. 2 provides a flowchart showing an assist control routine which theECU 50 executes. Execution of this assist control routine includes correction of the intake air flow. - At the
first step 100 of the routine shown inFIG. 2 , signals entered into theECU 50 from individual sensors are processed. In the assist control, signals from theaccelerator opening sensor 56, enginerotation speed sensor 54, turborotation speed sensor 32 andair flow meter 52 are used. - At the
next step 102, it is judged based on the input signals processed atstep 100 whether a predefined “assist start/continue” condition is met. Specifically, theECU 50 refers to an operating state judgment map prepared in advance, and from the engine rotation speed and accelerator opening, judges whether the current operating state of the engine needs motor assist. Motor assist is judged needed, for example, if a higher torque is needed although the exhaust energy is too low to drive the MAT 30 (low speed and high load state). If the current operating state of the engine needs motor assist, the “assist start/continue” condition is met. On the other hand, if the operating state does not need motor assist, this routine terminates since the “assist start/continue” condition is not met. - If the “assist start/continue” condition is met at
step 102,step 104 and the subsequent steps are performed. Firstly, atstep 104, a target turbo rotation speed is determined for theMAT 30 based on the input signals processed atstep 100. Specifically, theECU 50 determines the target turbo rotation speed from a multi-dimensional map (motor control map) where the engine rotation speed, accelerator opening and throttle opening are represented along their corresponding axes. After the target turbo rotation speed is determined, theECU 50 supplies power to theelectric motor 30 c according to the target turbo rotation speed to start the assist by theelectric motor 30 c (step 106). - During execution of the motor assist, it is judged whether a “
bypass valve 42 open” condition is met (step 108). The “bypass valve 42 open” condition means that thecompressor 30 a has reached the surge limit. Whether the surge limit is reached can be judged from the pressure ratio of the output pressure to the input pressure (atmospheric pressure) of thecompressor 30 a and the intake air flow indicated by the signal of theair flow meter 52. If the relation between the pressure ratio and the intake air flow exceeds a predefined surge line, it is judged that thecompressor 30 a has reached the surge limit. - If a pressure sensor is disposed between the
compressor 30 a and thethrottle valve 20, the output pressure of thecompressor 30 a may be measured from the signal of this pressure sensor. In the present embodiment, however, the output pressure of thecompressor 30 a is calculated from the turbo rotation speed measured by the turborotation speed meter 32 and the intake air flow. Specifically, the output pressure of thecompressor 30 a is determined from a map where the turbo rotation speed and the intake air flow are represented along their corresponding axes. - If the “bypass valve open” condition is met at
step 108, namely thecompressor 30 a has reached the surge limit, thebypass valve 42 is opened (step 110). Thebypass valve 42 is normally closed. If thebypass valve 42 is opened, the air compressed by thecompressor 30 a is partly returned to the upstream of thecompressor 30 a through thebypass passage 40. Thus, thecompressor 30 a is prevented from causing surge since air-bypass is performed to increase the amount of air which passes thecompressor 30 a. - If the
bypass valve 42 is opened to perform air-bypass atstep 110, the amount of air flowing through thebypass passage 40 settles to a certain steady level. After the steady level is reached, the intake air flow indicated by the signal of theair flow meter 52 agrees with the amount of air which is actually inhaled into theengine body 2. However, until thebypass passage 40 is filled with air to settle the amount of air flowing through it, more air is inhaled into theintake passage 8 than inhaled actually into theengine body 2. Therefore, a transient difference occurs between the intake air flow indicated by the signal of theair flow meter 52 and the air flow inhaled into theengine body 2. - Accordingly, correction of the intake air flow measured from the signal of the
air flow meter 52 is performed atstep 112 until the bypass air flow settles to a steady level. Specifically, according to equation (1) below, the amount of air which is actually inhaled into the engine body 2 (actual intake air flow) is calculated by subtracting the amount of bypassed air (bypass air flow) from the amount of intake air measured from the signal of the air flow meter 52 (measured intake air flow). The bypass air flow can be calculated from the pressure difference between the upstream and downstream of thebypass valve 42, or the difference between the output pressure and input pressure (atmospheric pressure) of thecompressor 30 a, and the aperture area of thebypass valve 42. -
Actual Intake Air Flow=Measured Intake Air Flow−Bypass Air Flow (1) - In a transient period immediately after air-bypass is started, the actual intake air flow calculated by the above equation (1) is used in the fuel injection amount control.
- If the bypass air flow settles after air-bypass was started, correction of the intake air flow according to the above-mentioned equation (1) is terminated. Since then, the intake air flow measured from the signal of the
air flow meter 52 is directly used in the fuel injection amount control. Whether the bypass air flow has settled can be judged from the change of the pressure difference between the upstream and downstream of thebypass valve 42, namely the change of the difference between output pressure and input pressure of thecompressor 30 a. - If the “
bypass valve 42 open” condition is not met atstep 108, that is, thecompressor 30 a has not reached the surge limit, air-bypass is not performed since processing ofstep 110 is skipped. In this case, the intake air flow is not corrected since processing ofstep 112 is also skipped. That is, while thebypass valve 42 is closed, the intake air flow measured from the signal of theair flow meter 52 is directly used in the fuel injection amount control. - At
step 114, it is judged whether a “bypass valve 42 close” condition is met. The “bypass valve 42 close” condition means that the surge of thecompressor 30 a is avoided. It is judged that the surge of thecompressor 30 a is avoided if the relation between the ratio of the output pressure to the input pressure of thecompressor 30 a and the intake air flow falls below the surge line. If the “bypass valve close” condition is met, that is, the surge of thecompressor 30 a is avoided, thebypass valve 42 is closed (step 116). If the “bypass valve close” condition is not met, thebypass valve 42 is kept open and processing of thestep 116 and the subsequent steps are skipped. - If the
bypass valve 42 is closed, it is judged at thenext step 118 whether a “motor assist stop” condition is met. Specifically, theECU 50 compares the actual turbo rotation speed measured by the turborotation speed sensor 32 with the target turbo rotation speed determined atstep 104. If the actual turbo rotation speed has reached the target turbo rotation speed, the “motor assist stop” condition is met. Until the “motor assist stop” condition is met, processing of thenext step 120 is skipped to continue the motor assist. If the “motor assist stop” condition is met, power supply from theECU 50 to theelectric motor 30 c is stopped to terminate the assist by theelectric motor 30 c (step 120). - According to the above-mentioned routine as described so far, it is possible to accurately calculate the intake air flow inhaled into the
engine body 2 even in a transient state which occurs immediately after air-bypass is started during execution of motor assist when air-bypass is performed in order to avoid surge by subtracting the bypass air flow from the amount of air inhaled into theintake passage 8. Therefore, the fuel injection amount control can be performed based on the accurate intake air flow. That is, it is possible to realize the target air-fuel ratio to satisfactorily maintain the exhaust emission and fuel efficiency even when air-bypass is performed in order to avoid surge. - Note that in the present embodiment, “calculation means” according to the first aspect of the present invention is realized by the
ECU 50 through execution of the aforementioned routine'sstep 112. In addition, “control parameter adjustment means” according to the first aspect of the present invention is realized by theECU 50 through execution of the fuel injection amount control based on the intake air flow corrected atstep 112. In addition, “surge avoidance means” according to the seventh aspect of the present invention is realized by theCPU 50 through execution ofstep 108. - In addition to the assist control which drives the
electric motor 30 a when a higher torque is actually needed, theECU 50 in the present embodiment can perform pre-assist control. The pre-assist control predicts a torque buildup request from the driver and raises the turbo rotation speed by driving theelectric motor 30 c before a higher torque becomes actually needed. - According to this pre-assist control, the time lag required for the boost pressure to be raised by the rotation of the
compressor 30 a can be eliminated. It is therefore possible to improve the output response to requests for higher torques for acceleration, climbing and so on. - Similar to the assist control, this pre-assist control is performed by a separate routine concurrently with the above-mentioned fuel injection amount control. During execution of the pre-assist control,
bypass valve 42 is opened to perform air-bypass so as to prevent thecompressor 30 a from causing surge while the turbo rotation speed is raised quickly. Therefore, as in the assist control, in a transient state immediately after air-bypass is started, a transient difference occurs between the amount of intake air measured from the signal of theair flow meter 52 and the amount of air inhaled actually into theengine body 2. - Accordingly, the fuel injection amount control and the pre-assist control are interrelated as described below in the present embodiment. The intake air flow is corrected according to the situation of the pre-assist control. The fuel injection amount can be controlled based on the corrected intake air flow.
FIG. 3 provides a flowchart showing an pre-assist control routine which theECU 50 executes. Execution of this pre-assist control routine includes correction of the intake air flow. - At the
first step 200 of the routine shown inFIG. 3 , signals entered into theECU 50 from individual sensors are processed. In the pre-assist control, signals from theaccelerator opening sensor 56, enginerotation speed sensor 54, turborotation speed sensor 32 andair flow meter 52 are used. Road information and vehicle information are also used in the pre-assist control. - At the next step, it is judged based on the input signals processed at
step 200 whether a predefined “pre-assist start/continue” condition is met. Specifically, theECU 50 judges whether the current traveling situation of the vehicle needs the pre-assist according to road information and vehicle information. The pre-assist is judged necessary if higher torque is expected to be required, for example, when the vehicle is going to be started on a slope, when the vehicle is approaching to an upward slope and when the vehicle is entering a straight road from a curved road. If the current traveling situation of the vehicle requires the pre-assist, the “pre-assist start/continue” condition is met. On the other hand, if the situation does not require the pre-assist, this routine is terminated since the “pre-assist start/continue” condition is not met. - If the “pre-assist start/continue” condition is met at
step 202,step 204 and the subsequent steps are performed. Firstly, atstep 204, a target turbo rotation speed is determined for theMAT 30 based on the input signals processed atstep 200. Specifically, theECU 50 determines the target turbo rotation speed from a multi-dimensional pre-assist map (motor control map) where the engine rotation speed, accelerator opening and throttle opening are represented along their corresponding axes. After the target turbo rotation speed is determined, theECU 50 supplies power to theelectric motor 30 c according to the target turbo rotation speed to start the assist by theelectric motor 30 c (step 206). - After the assist by the
electric motor 30 c is started, thebypass valve 42 is opened (step 208). Since opening thebypass valve 42 bypasses the output side to the input side of thecompressor 30 a, the rise of the output pressure of thecompressor 30 a is suppressed although the turbo rotation speed rises. This makes it possible to quickly raise the turbo rotation speed to the target speed while avoiding the surge of thecompressor 30 a. - While air-bypass is being performed following the opening of the
bypass valve 42 atstep 208, the intake air flow measured from the signal of theair flow meter 52 is corrected at thenext step 210. At this step, correction is done by smoothing the signal of theair flow meter 52. Namely, the intake air flow is measured from the smoothed signal. Note that although the signal is usually smoothed to remove noise, the signal is smoothed here several ten times more than usual. Determining the intake air flow from the smoothed signal can approximate the air flow inhaled actual into the engine body 2 (actual intake air flow) as shownFIG. 4 , resulting in a reduced difference between the intake air flow measured from the signal of theair flow meter 52 and the actual intake air flow. - At
step 212, it is judged whether a “bypass valve 42 close” condition is met. The “bypass valve 42 close” condition means that a torque buildup request is issued from the driver. Whether a torque buildup request is present can be judged from the engine rotation speed and the accelerator opening. If a torque buildup request is issued, thebypass valve 42 is closed (step 214) to raise the output pressure of thecompressor 30 a. On the other hand, if the “bypass valve close” condition is not met, thebypass valve 42 is kept open and processing ofstep 214 and the subsequent steps are skipped. - If the
bypass valve 42 is closed, it is judged at thenext step 216 whether a “motor assist stop” condition is met. Specifically, theECU 50 compares the actual turbo rotation speed measured by the turborotation speed sensor 32 with the target turbo rotation speed determined atstep 204. If the actual turbo rotation speed has reached the target turbo rotation speed, the “motor assist stop” condition is met. Until the “motor assist stop” condition is met, processing of thenext step 218 is skipped to continue the motor assist. If the “motor assist stop” condition is met, power supply from theECU 50 to theelectric motor 30 c is stopped to terminate the assist by theelectric motor 30 c (step 218). - According to the above-mentioned routine as described so far, it is possible to accurately determine the amount of air inhaled into the
engine body 2 by smoothing the signal of theair flow meter 52 to reduce the difference between the intake air flow measured from the signal and the actual intake air flow into theengine body 2 when air-bypass is done during execution of the pre-assist. Therefore, the fuel injection amount control can be performed based on the accurate intake air flow. That is, it is possible to realize the target air-fuel ratio and satisfactorily maintain the exhaust emission and fuel efficiency even during the pre-assist. - Note that in the present embodiment, “calculation means” according to the first aspect of the present invention is realized by the
ECU 50 through execution of the aforementioned routine'sstep 210. In addition, “control parameter adjustment means” according to the first aspect of the present invention is realized by theECU 50 through execution of the fuel injection amount control based on the intake air flow corrected atstep 210. In addition, “torque buildup request prediction means” and “pre-assist means” according to the eighth aspect of the present invention are realized by theCPU 50 through execution ofsteps - Although the intake air flow during the pre-assist is corrected in the above-mentioned embodiment by smoothing the signal of the
air flow meter 52, it is also possible to use simpler correction methods. One example is to predict the maximum intake air flow into theengine body 2 from the engine rotation speed and throttle opening and set the maximum value as the upper limit of the intake air flow. By restricting the intake air flow measured from the signal of theair flow meter 52 below the upper limit, it is possible to approximate the actual air flow into the engine body 2 (actual intake air flow) or reduce the difference between the intake air flow measured from the signal of theair flow meter 52 and the actual intake air flow. - In addition, although in the above-mentioned embodiment, the
bypass valve 42 is opened immediately after the motor assist is started for pre-assist, thebypass valve 42 may be kept closed in the same manner as the assist control routine until thecompressor 30 a reaches the surge limit. Correction of the intake air flow by smoothing the signal of theair flow meter 52 or setting an upper limit to the intake air flow can be executed immediately after the motor assist is started regardless of whether thebypass valve 42 is opened or not. - The following describes a second embodiment of the present invention with reference to
FIG. 6 . - A control apparatus for an internal combustion engine having a motor-driven supercharger, according to the present embodiment, is also implemented in the same configuration as
FIG. 1 . In the present embodiment, however, the control apparatus is implemented by making theECU 50 execute a routine shown inFIG. 6 instead of the routine shown inFIG. 3 . - The present control apparatus embodiment is different in terms of pre-assist control processing from the first control apparatus embodiment.
FIG. 6 provides a flowchart showing a pre-assist control routine which is executed by theECU 50. Each step of processing in the routine ofFIG. 6 is given the same step number as the corresponding step, if any, in the routine ofFIG. 3 if there is no difference in terms of processing. In addition, description of processing is omitted unless not already described. - In the pre-assist control according to the present embodiment as shown in
FIG. 6 , thebypass valve 42 is opened (step 220) before motor assist is started. That is, the outlet side of thecompressor 30 a is bypassed by the openedbypass valve 42 to the inlet side before theECU 50 starts the assist of theelectric motor 30 c by supplying power, which is determined according to the target turbo rotation speed, from theECU 50 to theelectric motor 30 c (step 222). - Since the
bypass valve 42 is opened before theelectric motor 30 c is started to run, compression of the intake air by thecompressor 30 a is suppressed, resulting in a smaller pressure difference between the inlet and outlet of thecompressor 30 a. Therefore, since the air which flows into thebypass passage 40 is suppressed, almost all of the air which passes thecompressor 30 a is directly inhaled into theengine body 2. - Therefore, since the difference between the intake air flow measured from the signal of the
air flow meter 52 and the actual air flow inhaled into theengine body 2 is very small, it is not necessary to correct the measured intake air flow in the present embodiment. That is, the fuel injection amount control can be done based on the accurate intake air flow by directly using the intake air flow measured from the signal of theair flow meter 52. - Note that in the present embodiment, “control parameter adjustment means” according to the ninth aspect of the present invention is realized by the
ECU 50 through execution of the fuel injection amount control. Likewise, “torque buildup request prediction means”, “pre-assist means” and “valve control means” according to the ninth aspect of the present invention are realized by theCPU 50 through execution ofsteps - The following describes a third embodiment of the present invention with reference to
FIGS. 7 and 8 . -
FIG. 7 schematically shows the configuration of an internal combustion engine having a motor-driven supercharger where a third control apparatus embodiment of the present invention is applied. Each component inFIG. 7 is given the same reference numeral as the corresponding one, if any, shown inFIG. 1 . In addition, configurational description is omitted unless not already described. - The engine according to the present embodiment is different from the engine according to the first embodiment in that an EGR is included. As shown in
FIG. 7 , anEGR passage 22 is connected to theintake passage 10 between thethrottle valve 20 and theintake manifold 4. The opposite end of theEGR passage 22 is connected to theexhaust manifold 6. TheEGR passage 22 is provided with anEGR cooler 26 to cool the EGR gas which flows therein. Downstream of theEGR cooler 26, theEGR passage 22 is provided with anEGR valve 24 to control the passage area of theEGR passage 22. TheseEGR passage 22,EGR valve 24 andEGR cooler 26 constitute an EGR apparatus. - Since the
intake passage 10 and theexhaust manifold 6 are connected by theEGR passage 22, part of the exhaust gas (EGR gas) is introduced into theintake passage 10 via theEGR passage 22. The amount of EGR gas introduced into the intake passage 10 (EGR flow) can be controlled by the opening of theEGR valve 24. The opening of theEGR valve 24 is controlled by theECU 50 based on the operating state of the engine. - Downstream of the connection with the
EGR passage 22, theintake passage 10 is provided aboost pressure sensor 58. Theboost pressure sensor 58 outputs a signal indicative of the internal air pressure of theintake passage 10. Since the air pressure in theintake passage 10 is consistent with the air flow therein, it can be said that theboost pressure sensor 58 outputs a signal indicative of the air flow in theintake passage 10. Therefore, from the signal of theboost pressure sensor 58, it is possible to measure the air flow inhaled into theengine body 2 via theintake passage 10. Theboost pressure sensor 58 is connected to the input side of theECU 50. The signal of theboost pressure sensor 58 is used by theECU 50 to control the engine. - The present control apparatus embodiment is different also in terms of assist control processing from the first control apparatus embodiment.
FIG. 8 provides a flowchart showing an assist control routine which theECU 50 executes in the present embodiment. Each step of processing in the routine ofFIG. 8 is given the same step number as the corresponding step, if any, in the routine ofFIG. 2 if there is no difference in terms of processing. In addition, description of processing is omitted unless not already described. - In the assist control according to the present embodiment, calculation of the amount of intake air is switched depending on whether the
EGR valve 24 is open. Specifically, as shown inFIG. 8 , after thebypass valve 42 is opened atstep 110, it is judged whether theEGR valve 24 is open (step 122). If theEGR valve 24 is closed, the air flow inhaled into theengine body 2 is calculated from the signal of the boost pressure sensor 58 (step 124). Using the signal of theboost pressure sensor 58 makes it possible to accurately calculate the air flow inhaled into theengine body 2 not under influence of the air-bypass. - However, when the
EGR valve 24 is open to introduce exhaust gas into theintake passage 10, the gas flow measured from the signal of theboost pressure sensor 58 is different from the air flow inhaled actually into theengine body 2 due to the exhaust gas flow. Therefore, when theEGR valve 24 is open, correction of the intake air measured from the signal of theair flow meter 52 is done in the same manner as in the first embodiment (step 112). - According to the above-mentioned routine, even when the EGR apparatus is active or when the
EGR valve 24 is open, it is possible to accurately calculate the intake air flow inhaled into theengine body 2 in a transient state immediately after air-bypass is started by subtracting the bypass air flow from the amount of air inhaled into theintake passage 8. Thus, even when exhaust gas is introduced into theintake passage 10, the fuel injection amount can be controlled based on the accurate intake air flow. - Note that in the present embodiment, “calculation means” according to the sixth aspect of the present invention is realized by the
ECU 50 through execution ofstep boost pressure sensor 58 corresponds to the “gas property sensor” according to the sixth aspect of the present invention. - While embodiments of the present invention have so far been described, the present invention is not limited to these specific embodiments. Various modifications may be done without departing from the spirit of the present invention. The following describes examples of such modifications.
- Pre-assist control in the first embodiment smoothens the signal of the
air flow meter 52 during the execution of air-bypass. The intake air flow measured from the smoothed signal is taken as the air flow inhaled into theengine body 2. This may be modified so as to smooth the signal of theair flow meter 52 only during a transient period just after air-bypass is started. Like the assist control, the air flow inhaled into theengine body 2 just after air-bypass is started may also be determined by correcting the intake air flow measured from the signal of theair flow meter 52, namely subtracting the bypass air flow from the measured intake air flow. - In addition, the third embodiment may be modified so as to perform the pre-assist control by using either the pre-assist control method in the first embodiment or that in the second embodiment. While the EGR apparatus is not active, the air flow inhaled into the
engine body 2 may also be calculated from the signal of theboost pressure sensor 58 in the same manner as the assist control in the third embodiment. - In addition, while the third embodiment has the
boost pressure sensor 58 disposed downstream of thethrottle valve 20 in theintake passage 10, an air flow meter which outputs a signal indicative of the air flow may be disposed in place of theboost pressure sensor 58.
Claims (12)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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JP2005180955A JP4595701B2 (en) | 2005-06-21 | 2005-06-21 | Control device for internal combustion engine having supercharger with electric motor |
JP2005-180955 | 2005-06-21 | ||
PCT/JP2006/311694 WO2006137279A1 (en) | 2005-06-21 | 2006-06-06 | Control apparatus for internal combustion engine having motor-driven supercharger |
Publications (2)
Publication Number | Publication Date |
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US20090222188A1 true US20090222188A1 (en) | 2009-09-03 |
US7793500B2 US7793500B2 (en) | 2010-09-14 |
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US11/817,347 Expired - Fee Related US7793500B2 (en) | 2005-06-21 | 2006-06-06 | Control apparatus for internal combustion engine having motor-driven supercharger |
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US (1) | US7793500B2 (en) |
JP (1) | JP4595701B2 (en) |
CN (1) | CN101163870B (en) |
DE (1) | DE112006001436B4 (en) |
WO (1) | WO2006137279A1 (en) |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
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US20080053091A1 (en) * | 2005-02-16 | 2008-03-06 | Pierre Barthelet | Turbocharging Device and Control Method for Controlling the Turbocharging Device |
US20110027066A1 (en) * | 2008-03-28 | 2011-02-03 | Mitsubishi Heavy Industries, Ltd. | Method of controlling turbine equipment and turbine equipment |
US20110174278A1 (en) * | 2010-01-15 | 2011-07-21 | Mitsubishi Electric Corporation | Power source control unit of electric supercharger |
US20130213037A1 (en) * | 2010-10-28 | 2013-08-22 | Isao Kitsukawa | Turbocharger system |
US20140251267A1 (en) * | 2013-03-07 | 2014-09-11 | Ford Global Technologies, Llc | Method and system for improving engine starting |
US20160281652A1 (en) * | 2013-12-20 | 2016-09-29 | Toyota Jidosha Kabushiki Kaisha | Control system for internal combustion engine |
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US9080506B2 (en) * | 2013-08-13 | 2015-07-14 | Ford Global Technologies, Llc | Methods and systems for boost control |
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KR101714265B1 (en) * | 2015-11-30 | 2017-03-23 | 현대자동차주식회사 | The controlling method of engine system equipped with supercharger |
DE102016200982A1 (en) * | 2016-01-25 | 2017-07-27 | Volkswagen Aktiengesellschaft | Method and control device for operating a drive device |
US9630611B1 (en) | 2016-02-03 | 2017-04-25 | Toyota Motor Engineering & Manufacturing North America, Inc. | System and method for acceleration event prediction |
JP6406301B2 (en) * | 2016-03-30 | 2018-10-17 | マツダ株式会社 | Engine control device |
FR3059720B1 (en) * | 2016-12-05 | 2020-01-24 | Renault S.A.S | METHOD FOR CONTROLLING AN ELECTRICALLY ASSISTED TURBOCHARGER |
US10316740B2 (en) | 2017-02-15 | 2019-06-11 | Borgwarner Inc. | Systems including an electrically assisted turbocharger and methods of using the same |
US10605161B2 (en) | 2017-05-18 | 2020-03-31 | Ford Global Technologies, Llc | Method and system for indicating degradation of boosted engine system |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4774812A (en) * | 1985-04-08 | 1988-10-04 | Mazda Motor Corporation | Turbocharged engine |
US6216676B1 (en) * | 1998-10-07 | 2001-04-17 | Toyota Jidosha Kabushiki Kaisha | Internal combustion engine system |
US6363721B1 (en) * | 1999-06-24 | 2002-04-02 | Avl List Gmbh | Internal combustion engine, in particular of the self-igniting type |
US20040206083A1 (en) * | 2003-04-16 | 2004-10-21 | Toyota Jidosha Kabushiki Kaisha | Control apparatus for internal combustion engine having motor-driven supercharger |
US6983597B2 (en) * | 2002-06-07 | 2006-01-10 | Robert Bosch Gmbh | Method and arrangement for controlling an internal combustion engine |
US20090107142A1 (en) * | 2007-10-29 | 2009-04-30 | Ford Global Technologies, Llc | Compression System for Internal Combustion Engine Including a Rotationally Uncoupled Exhaust Gas Turbine |
US20090198432A1 (en) * | 2006-08-10 | 2009-08-06 | Masakazu Tabata | Control apparatus for internal combustion engine with supercharger |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4210070C2 (en) * | 1992-03-27 | 1996-10-17 | Daimler Benz Ag | Combined-charge internal combustion engine |
DE19835594A1 (en) | 1998-08-06 | 2000-02-10 | Audi Ag | Multi-cylinder internal combustion engine has first and further induction tracts plus first and further exhaust tracts communicating together upstream of exhaust turbochargers. |
JP2001123844A (en) * | 1999-10-29 | 2001-05-08 | Honda Motor Co Ltd | Fault detecting device for electrical supercharger |
DE10164790A1 (en) * | 2001-11-30 | 2003-07-10 | Audi Ag | Method and device for pre-activating at least one shock absorber of a motor vehicle |
JP3952974B2 (en) * | 2003-03-17 | 2007-08-01 | トヨタ自動車株式会社 | Control device for internal combustion engine |
SE525097C2 (en) * | 2003-04-24 | 2004-11-30 | Volvo Lastvagnar Ab | Methods of controlling overcharging in an internal combustion engine and vehicles with an overcharged internal combustion engine with electronic control means for controlling the overcharging |
JP4134816B2 (en) * | 2003-06-03 | 2008-08-20 | いすゞ自動車株式会社 | Turbocharged engine |
JP2007071116A (en) * | 2005-09-07 | 2007-03-22 | Toyota Motor Corp | Turbocharger system with motor-driven assist function |
-
2005
- 2005-06-21 JP JP2005180955A patent/JP4595701B2/en not_active Expired - Fee Related
-
2006
- 2006-06-06 US US11/817,347 patent/US7793500B2/en not_active Expired - Fee Related
- 2006-06-06 DE DE112006001436T patent/DE112006001436B4/en not_active Expired - Fee Related
- 2006-06-06 WO PCT/JP2006/311694 patent/WO2006137279A1/en active Application Filing
- 2006-06-06 CN CN2006800136378A patent/CN101163870B/en not_active Expired - Fee Related
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4774812A (en) * | 1985-04-08 | 1988-10-04 | Mazda Motor Corporation | Turbocharged engine |
US6216676B1 (en) * | 1998-10-07 | 2001-04-17 | Toyota Jidosha Kabushiki Kaisha | Internal combustion engine system |
US6363721B1 (en) * | 1999-06-24 | 2002-04-02 | Avl List Gmbh | Internal combustion engine, in particular of the self-igniting type |
US6983597B2 (en) * | 2002-06-07 | 2006-01-10 | Robert Bosch Gmbh | Method and arrangement for controlling an internal combustion engine |
US20040206083A1 (en) * | 2003-04-16 | 2004-10-21 | Toyota Jidosha Kabushiki Kaisha | Control apparatus for internal combustion engine having motor-driven supercharger |
US20090198432A1 (en) * | 2006-08-10 | 2009-08-06 | Masakazu Tabata | Control apparatus for internal combustion engine with supercharger |
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Also Published As
Publication number | Publication date |
---|---|
CN101163870A (en) | 2008-04-16 |
CN101163870B (en) | 2010-11-17 |
WO2006137279A1 (en) | 2006-12-28 |
US7793500B2 (en) | 2010-09-14 |
JP4595701B2 (en) | 2010-12-08 |
DE112006001436T5 (en) | 2008-04-30 |
DE112006001436B4 (en) | 2013-01-31 |
JP2007002687A (en) | 2007-01-11 |
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